<template>
  <div class="todo-footer" v-show="todoLength">
    <label>
      <!--      <input type="checkbox" :checked="isAll" @change="handleChange"/>-->
      <input type="checkbox" v-model="isAll"/>
    </label>
    <span>
          <span>已完成{{ todoChecked }}</span> / 全部{{ todoLength }}
        </span>
    <button class="btn btn-danger" @click="clearDone">清除已完成任务</button>
  </div>
</template>

<script>
export default {
  name: "Footer",
  props: {
    todos: Array,
    changeAll: Function,
    clearDone:Function,
  },
  computed: {
    todoChecked() {
      return this.todos.reduce((pre, current) => pre + (current.done ? 1 : 0), 0)
    },
    todoLength() {
      return this.todos.length
    },
    isAll: {
      get() {
        return this.todoLength === this.todoChecked && this.todoLength > 0
      },
      set(value) {
        this.changeAll(value)
      }
    }
  },
  methods: {
    handleChange(e) {
      this.changeAll(e.target.checked)
    }
  }
}
</script>

<style scoped>

/*footer*/
.todo-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.todo-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.todo-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.todo-footer button {
  float: right;
  margin-top: 5px;
}

</style>
